Tory MP Douglas Carswell was stirring it up on Newsnight the other night declaring that taxpayers in the UK had had enough of bailouts and it was time to stop handing out good money after bad to Greece, Ireland and Portugal. He had it all worked out.

British taxpayers would end up paying another 2p in the pound income tax, he pronounced, to cover the £22bn already committed to the three countries. Carswell should go back to school, at least as far as Ireland is concerned. Because the €3.8bn (£3.4bn) the UK has committed to Ireland in a unilateral loan won't cost the taxpayer anything.

In fact, it will make the taxpayer money because the UK is charging a very nice 5.9% interest rate on the loan, which will be sourced by the UK Treasury at anything but that rate. In total the UK has committed £7bn to Ireland: £3.4bn in the unilateral loan and the remainder as part of the overall IMF/EU bailout, which is being charged at an average rate of 5.8%.

We don't know at exactly what rate the money is being borrowed by the UK Treasury (the unilateral loan hasn't been drawn down yet) but the interest rates on UK gilts will give you an idea of what kind of profit can be made by Britain on the Irish bailout.

UK three-year gilts are trading at 1.03% while seven-year gilts are trading at 2.46% (the cost of seven-year gilts). Quite a lot lower than the 5.9% interest rate on the UK loan or the 5.8% on the IMF/EU loan. Anything but a bailout.

Yet Carswell had this to say on Newsnight:

"For the past 13 months , the government has, in effect, been increasing our contingent liability to bailing out the eurozone by something like £21bn.

"To put that in context that's 2p in the pound income tax. That could double the size of the British army.

"That is a huge amount of money and I'm pleased that we are now changing course and we are now beginning to realise that we cannot continue to throw ever greater liability to sort out a problem not of our own making."

He might have a point about Greece because there is a strong chance of it defaulting, but Ireland is hoping it won't need the entire UK loan.

"Our preference would be not to draw down the loan at all. If we can go back to the markets next year, then the idea is we won't need to call on it," said a spokesman for Ireland's department of finance.

Of course, there is a strong chance Ireland won't be able to return to the markets next year, but that's another story.

For the purpose of my argument, the point is that Ireland's "bailout" isn't a bailout at all. It's a great big loan charged at above market rates.